The present invention relates to membrane electrode assemblies and, more particularly to such assemblies for fuel cells, especially for proton exchange membrane (PEM) fuel cells.
PEM fuel cells include a membrane electrode assembly (MEA) which typically includes an anode and cathode on either side of a membrane wherein fuel is fed to the anode, and oxygen to the cathode, and the resulting reaction generates electricity.
Unfortunately, current membrane technology produces stacks of cells including such membranes having useful lifetimes as short as about 1,000 hours which is well short of ultimate goals. When a membrane fails, failure occurs suddenly and ends the useful life of the cell, thereby necessitating immediate intervention. Cells can be excised from a stack for replacement, but will require great care and nevertheless will be accompanied by potential loss of adjacent cells. This type of replacement process is not a viable field service, and it is likely that once membrane failure begins, a stack replacement will be required.
It is clear that the need remains for membranes for fuel cell assemblies and the like which have longer useful lifetimes.
It is therefore the primary object of the present invention to provide a membrane electrode assembly having enhanced useful lifetime.
Other objects and advantages will appear hereinbelow.